Century-old limit on turning heat into electricity surpassed, enabling ultrasensitive temperature sensing

Scientists have discovered that a crystalline semiconductor made of heavily doped, highly compensated scandium nitride thin films can convert temperature differences into electrical voltage at a scale nearly a thousand times larger than textbook physics allows. Surpassing the traditional Seebeck coefficient ceiling of solids and even liquid electrolytes, this solid-state material exhibits a thermopower exceeding –124.6 millivolts per Kelvin near room temperature. Researchers from JNCASR, the University of Sydney, and IISc Bangalore grew these epitaxial films using ultrahigh-vacuum magnetron sputtering. The discovery enables applications in ultrasensitive temperature sensors, thermal imaging, quantum sensing devices, and a preliminary prototype photon sensor.